Along with development of technology, various display devices are continually developed. In some display devices, besides that a viewer may view images displayed on a display panel, the viewer may also see through the display panel to view a scene behind the display panel. These display devices are adaptable for commercial windows, head up display of vehicles and so on and thus gradually draw more and more attentions because of their light-transmitting characteristic.
If the overall transparency of a display device is too low, the user would observe the existence of the display device, which makes the background behind the display device unlikely to be seen clearly. In addition, it is an issue to improve the moisture and/or the oxygen barrier properties of electronic devices and display panels through the packaging technology, thereby enhancing the reliability and the lifetime of electronic devices and display panels.